Across a galaxy of shifting dimensions, a sudden surge of magical portals pulls heroes from disparate teams into a single, perilous moment. The story centers on Haruto Soma, who wields the enigmatic power of the wizard, and Koyomi, a resourceful companion who finds herself drawn into events beyond her world. As portals flare to life, a desperate clash erupts when Geki Jumonji—the formidable Space Sheriff who also bears the mantle of Space Ikadevil’s threats—tries to end the wizard’s presence, arguing that magic could destabilize universal peace. In the heat of the confrontation, Haruto chooses to shield Koyomi and a vulnerable child, a selfless act that earns the respect of Space Sheriff Gavan. Seeing the danger posed by the battle’s collateral damage, Gavan decides to step back, signaling that the true menace lies beyond their immediate skirmish.
The crisis draws the attention of the Galactic Union, and Haruto travels to brief his superiors, including the seasoned Retsu Ichijouji. The exchange reveals a delicate truth: Haruto is not a declared foe of the Union or its operatives, but the political landscape is tense. When Geki refuses orders to wipe out the Kamen Riders Wizard and Beast, Retsu relieves him of duty and tasks Kai, the Space Sheriff Sharivan, with the corrective mission. The decision sets in motion a rivalry of loyalties and a test of who truly guards the balance of the cosmos.
Meanwhile, on a distant shore of danger, Yoko Usami—a Go-Buster with her buddy droid Usada Lettuce—detects a strange object crash-landing nearby. Yoko Usami is drawn to a small robot who names itself Psycholon, a discovery that will tether her fate to a larger, unfolding threat. As Yoko begins to restore and understand the robot, she discovers that Psycholon has no clear memory of his past, and their budding friendship offers a glimmer of hope in a universe under strain. But their fragile partnership is interrupted when a barrage of Kamen Rider monsters ambushes them, and Yoko regains her Yellow Buster abilities just as her teammates are pulled into a portal meant for her and Psycholon.
From there, events escalate quickly. Haruto faces a renewed onslaught of Shocker forces and encounters Space Ikadevil of the revived Space Shocker, who seeks Psycholon for his own ends. Transported through a portal, Haruto meets the Kyoryugers only to be mistaken for a Debo Monster, and the encounter becomes a catalyst for a broader alliance when Gai Ikari—the roguish, unconventional warrior who arrives with the Gokaigers—steps in to interrupt a duel and explain who the true instigator is: Space Shocker’s machinations. Gai’s revelations connect Haruto’s wizardry with the wider network of protectors, and Haruto learns that the Space Galactic Union suspects him and Kosuke Nito as the source of the chaos.
As the tension radiates outward, Daigo Kiryu and the other teams appear in the fray, bringing together a chorus of legendary fighters from a spectrum of worlds. Sharivan’s arrival, followed by the Gokaigers’ Gai Ikari, anchors a coalition that includes the Gachic fleets and a cadre of legendary protectors. Yet trust remains fragile, and Geki’s stubborn insistence on his own path tests every alliance. The Genmu Fortress looms as a looming threat, its magic fueled by Strategist Raider of the fallen space crime syndicate Madou, who plans to drag Earth into the Genmu World.
Despair gives way to resolve when Gai arrives at the Omokagedō Antique Shop to share crucial truths about Madou’s plan. The only viable option to avert catastrophe, the Grand Birth and Vavilos-driven response, would be the Super Dimensional Cannon—but Haruto and his companions refuse to let Earth become collateral for cosmic power. Geki refuses to surrender, and he convinces Kai to pursue a plan that buys time for a last-ditch defense. With one hour to act, Haruto leads a daring expedition into Genmu World alongside Yoko, Psycholon, and Nito to halt the invasion at its source.
In Genmu World, the group’s revelatory collaborations begin to take shape. Kamen Rider Beast Kousuke Nitou holds the line against Space Kumo Otoko while the Livemen, the Gingamen, the Gekirangers, and Riders from Amazon and Hibiki surge in to support. A key turning point comes when Gavan Type-G, aided by the Shinkengers’ Kotoha Hanaori Kotoha Hanaori, finally unlocks the transformation system so Haruto can don a new form and join the struggle with renewed might. The team receives reinforcements from Fourze Kamen Rider Fourze and other legendary allies, including the Gokaigers and the Dekarangers, who lend their powers to push back the assault.
As the Genmu Castle becomes the epicenter of the battle, the Yellow Buster squad faces Reider and Shadow Moon. Psycholon’s teleportation gives their friends a way out of captivity, just as Wizard’s arrival dispels the Genmu Space and clears space for a wider assault. The Kyoryugers, Space Sheriffs Sharivan and Shaider, and a host of Kamen Riders—Fourze, Meteor, OOO, and others—combine their strengths to avert catastrophe. Shadow Moon is finally defeated by the Kyoryugers, and the moment of truth arrives as Reider is mortally wounded by a Dragon Breath/Kentrospiker combo.
In a pivotal turn, Retsu fires the Super Dimensional Cannon to halt a chain reaction, but Reider reveals that the blast will revive Demon King Psycho. Gavan makes a selfless choice, using the Dolgiran to negate the blast while Sharivan and Shaider join in to stabilize the situation. The energy produced becomes the catalyst for Psycholon’s revelation and for a transformed, final push. Psycholon is discovered to be part of Psycho’s body, and the heroes stand at the cusp of an all-out clash with a revived, army of Super Sentai monsters. Just as all seems lost, Kamen Rider 1 [Tetsu Inada] and a reinvigorated Kamen Rider Wizard join the effort to push back the invaders, aided by Gavan and the Gokaigers.
In the climactic confrontation, WizardDragon energizes Kyoryuzin to a brutal, decisive strike, and Yellow Buster reaches Psycholon through the RH-03 device, breaking Psycho’s hold over him. The Space Sheriffs’ fleets unleash a coordinated Big Grand Fire to prevent Psycho from escaping Earth’s atmosphere, while Kyoryuzin’s Brave Strike End finally destroys Psycho’s core. With Psycho defeated, the heroes disperse, and the people of Earth are left with the promise that they can repair Psycholon. Gai Ikari returns to his duties with a new understanding of universal peace and responsibility toward Earth, while the others fade back to their respective dimensions, guardians of their own corners of the multiverse.
In the post-credits scene, a mysterious blue and red figure appears and states that “They are not the only heroes of Earth,” hinting at new adventures beyond the horizon. > They are not the only heroes of Earth
This sprawling crossover blends a chorus of iconic champions, weaving their strengths, loyalties, and personal journeys into a single, sprawling defense of reality itself. The result is a celebration of teamwork across universes, where old friendships are tested, new alliances are formed, and the line between hero and protector blurs under the weight of a shared destiny.
